The present invention relates to the protection of exposed structures, in particular cables, poles, and pipes, from destructive encounters with external threats, including: animals (including man), plants, environmental hazards, and machines. In particular, the present invention relates to protective configurable sheaths for exposed structures.
The use of tubing or a jacket to manufacture a cable or modify a cable is well-known. The tubing or jacket introduces protective attributes such as weather-resistance, insulation, chemical resistance, fire resistance, abrasion resistance, EMI shielding, etc. which typically require that the tubing or jacket be a continuous covering. Stretchable tubing, heat shrinkable tubing, and jackets with zippers, snaps, or Velcro-like adhesives are commercially available (see xe2x80x9cThe Zipper Tubing Co.xe2x80x9d for example). The present invention can be understood by considering the problems encountered while trying to protect exposed structures such as cables, poles, pipes, towers, etc. from attack by animals (and plants). For example, buried cables may be attacked by burrowing animals or animals that dig holes. Underwater cables will often be targeted by fish (including crustaceans) as potential food, as intruders, as building materials, or for refuge. The presence of certain marine biology can in turn attract other species of marine biology, compounding the problem. Suspended cables such as power lines or telephone/cable-TV lines may provide a friendly environment which could encourage plant growth or attract animals such as birds, bats, cats, squirrels, rats, opossums, raccoons, snakes, monkeys, koalas, etc. The presence of plants can add unnecessary weight to, create fire hazards for, attract animals and other plants to, and obscure the location of the exposed structure.
Animals may shorten the useful life of cables by eating, biting, clawing, or rubbing the cable (which might produce catastrophic results or create an opportunity to inflict further damage by other animals, plants, and environmental factors such as moisture, heat, cold, wind); through biochemical means; or by hanging from/sitting on the cables. Thus there is a need for a protective, configurable sheath (also referred to as a configurable sheath or simply as a sheath) which can be attached to new and existing exposed structures, including cables. Various factors such as weight, ease of customization, upgrade, repair, installation, and removal will influence sheath design considerations. Animals may create cavities in trees or poles and animals may climb on trees, poles, towers, pipes, or ducts (as well as into pipes and ducts). These acts may result in the destruction of or loss of functionality of the exposed structure itself (or equipment such as electrical or monitoring devices attached to the exposed structure). Plants such as vines may attach to the exterior (or interior) of an exposed structure, introducing mechanical stress, creating possible fire hazards, and attracting animals (and plants). Small animals may bring building materials and leave waste products in a duct. Existing protective devices such as barbed wire tend to be heavy (since it needs to be self-supporting and is targeted at large animals) and it employs a fixed pattern of barbs (so it is not upgradeable or configurable on-site). Typically, barb wire is used only for containment and is not well suited for preventing interference with an exposed structure. Thus there is a need for a configurable sheath which can be attached to new and existing exposed structures in addition to cables. The protective, configurable sheath design can be customized or tuned for use with a variety of exposed structures (cables, pipes, tubing, ducts, chains, wiring, trees, poles, towers, antennae, fences, vehicles, animals, etc.). The tuning process may involve adding, remove, or modifying passive or active components (features). A sheath which includes one or more embedded or attached active components can be described as a protective intelligent configurable sheath or simply an intelligent sheath. In certain situations the functions of a configurable sheath with passive and/or active components can be provided by the judicious placement of the components on or within the exposed structure. The sheath base material can be omitted. A sheath which includes active and/or passive components but no sheath base can be described as a protective structured configurable sheath or simply a structured sheath.
Exposed structures are often difficult to maintain or protect because these structures are extended in one or more dimensions. Determining how and from where the exposed structure is being threatened (plants, animals, environmental hazards, machines) and initiating an active response (on some level) can be crucial for the long-term viability of the exposed structure. In addition, knowing the magnitude and location of the threat may influence the choice and magnitude of the response. It may be desirable to increase or reduce the visibility of the exposed structure. For example, in many instances hanging cables are difficult to detect by electrical or magnetic means; with ionizing or non-ionizing radiation such as electromagnetic (EM) or acoustic radiation; by the presence of chemical compounds in the air; or by the manner in which they modify the local environment. Hanging cables can create hazards for airborne objects such as planes, helicopters, gliders, birds, bats, etc. and surface-dwelling animals. Buried or underwater cables may be difficult to detect using acoustic, neutron or EM radiation, or by electrical or magnetic means. Poles or antennae may represent flight hazards or obstructions in some situations and targets in other situations. The use of a configurable sheath would be beneficial for these and related applications. Prior devices and methods do not address these concerns.
The present invention is an apparatus and method which address the problem of protecting exposed structures, in particular cables, poles, ducts, and pipes from direct and indirect threats posed by various animals, plants, environmental hazards, and machines and other external threats. For exposed structures such as ducts and pipes, the exterior and/or the interior of the exposed structure may require protection. A partial listing of exposed structures which can benefit from the use of this invention include cables, poles, ducts, pipes, tubing, chains, wiring, railing, fences, piers, towers, antennae, buildings, vehicles, boats, planes, roofs, gutters, trees, etc. Versions of this invention can be worn by an animal at risk. A protective configurable sheath (also referred to as a configurable sheath or a sheath) can be customized in order to target one or more environmental, animal, and plant problems. Threats posed by machines can also be targeted. A sheath fully or partially encompasses the exposed structure (such as a cable) to be protected. The sheath can be designed to be permanent, removable, degradable, or upgradable. In one embodiment of the present invention, a sheath for a cable or other like structure is disclosed wherein the sheath may be attached manually or by an automated assembly system before, during, or after cable installation. This permits customization of commercially-available, mass-produced cabling as well as retrofitting of installed cable.
A prefabricated sheath base in sheet, strip, or mesh form may be attached to an exposed structure by mechanical means (an adhesive; a tie, band, a hook-and-loop system; a zipper, a clip, a snap, a screw, a mechanical insert; by using heat, chemical, optical, electrical, or acoustic means to seal a seam, etc.). An alternate installation method is to apply the sheath directly to the exposed structure by spraying or pouring a quick-setting base material such as a plastic or rubber to form a continuous sheath base or a non-continuous (structured) sheath base (such as a pattern comprised of dots, strips, grids, etc.). Passive and active components (features) such as spikes, disks, dispensers, sensors, sources (including transmitters and electronic displays), MEMS, electroactive polymeric actuators, etc.) can be embedded in the sheath base or they can be attached to the sheath base at appropriate locations. Yet another implementation of a configurable sheath is a non-continuous (structured) sheath design which utilizes the exposed structure itself to provide the sheath base to which components are attached. Examples of existing exposed structures which could function as a sheath base include a cable jacket, a pole, a duct, a pipe, etc. Thus, in this implementation the configurable sheath is assembled from individual components attached at appropriate locations along the base provided by the exposed structure. A component such as a spike could be mounted mechanically, magnetically, glued, etc. directly to the surface of the exposed structure at designated locations.
A number of configurable sheath properties can be customized. For example, the sheath can be continuous (a sheet, a mesh, a strip) or structured (a set of disks, a pattern of dots, a pattern of strips, a grid pattern). The sheath may be inflatable or capable of motion. The sheath may incorporate passive and active components (devices). The sheath base can have grooves or rails. The types of conventional materials used to make a sheath base are similar to those used to make cable jackets or tubing (plastic, rubber, latex, impregnated cloth, fire retardant, metal foil, wire, adhesives, etc.). The flexibility inherent in the configurable sheath design permits the use of unconventional base materials (such as Lithium-polymers which can be used in thin, flexible polymer batteries) which can serve more than one purpose (such as a power source, an acoustic or EM source, a display source, an electroactive polymeric actuator, a sensor). Configurable sheath designs can exploit the ability of colors and patterns to warn, attract, or conceal. The chemical and physical properties of the sheath base material (including mechanical properties, weight distribution, resistance to environmental degradation, etc.) and the chemical and physical properties of any components (spikes, disks, sensors, sources, dispensers, etc.) which are embedded or attached to the sheath can be can be optimized as needed. For example, spike properties which can be tailored for a specific application include the distribution of spike sizes, shapes, and patterns; rigidity, material composition, mobility, and internal/external framework. Spikes can be integrated into the sheath base or they can be detachable (and thus replaceable). Detachable spikes can be designed to function in a manner similar to plant thorns or burrs or as launchable projectiles.
A spike can dispense an agent, imitating the function of a spine or spicule which provides protection for certain types of fish or sponges. Agents are consumable materials which can possess attractive, repellant, awareness-enhancing, irritating, or disabling/neutralizing properties. The material composition of the spikes (and any agents they dispense) can be formulated so that they are biodegradable. An agent can be also be dispersed by other dispensing mechanisms including atomizers, pressurized sprayers, or squatters; by sublimation or evaporation; or by a mechanical method. Examples of mechanical agent dispersion devices include mechanisms such as food pellet dispensers. Familiar dispersion devices are used in common household products such as pump sprays and pressurized spray cans; solid air fresheners, insect and pest (scent/odor-baited) traps; or poison dispensers and food dispensers. The agent dispersion device can be designed such that it can be armed or disarmed manually or remotely.
The electric, magnetic, EM, and acoustic properties of the configurable sheath base material (and embedded and attached components) may be customized. As explained, the sheath base can incorporate energy-conversion devices such as solar cells and heat converters for power generation as well as energy storage devices such as batteries and capacitors. An alternative is to treat these devices as components and embed or attach them to the sheath base. The sheath may be designed so as to hide an exposed structure such as a cable by reducing the detection cross section of the cable or by reducing the presence of indicators such as nearby animals or plants. Under different conditions the sheath may be designed as to increase the visibility (in general or selectively) of the exposed structure. For example, cable detectability can be affected by utilizing colored paints or phosphorescent, fluorescent or reflective paint in appropriate patterns; holographs, gratings, and other devices which reflect, scatter, conduct, absorb, or convert incident radiation; materials with energydependent radiation attenuation cross sections; LED""s, laser diodes, and other EM transmitters; piezo-electric vibrators and other transducers, physical structures to create sound, etc.). Intelligent configurable sheath designs can incorporate active features (with or without passive features) such as the ability to communicate with other active components, the sheath base, or external devices; to perform monitoring and self-maintenance; and to react to threats directly. Active components differ from passive components since they are capable of performing controlled actions which depend on events or situations occurring within their surroundings (for example, by acquiring or transmitting data, implementing signal processing, making simple or complex decisions, converting or storing energy, causing physical movement, etc.). The intelligent sheath may also alert an external device (such as a remote processing and response system) to disperse an agent, emit a sound, fire a weapon, transmit a distress signal, etc. An intelligent sheath can employ proactive and reactive techniques in an effort to fine-tune its protective capabilities. Flexible design parameters ensure that the sheath can be tailored to address threats to cables and other exposed structures for a variety of circumstances.